Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Manipulated Gamma Spectroscopy:

Methodologies and Applications

Saed Dababneh•Al-Balqa Applied University, JORDAN.• Forschungszentrum Karlsruhe, GERMANY.• University of Notre Dame, USA.• Joint Institute for Nuclear Astrophysics, USA.• CERN.

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Why … ?• Efficiency• Signal-to-Background Ratio• Correction Factors• Interference• True Coincidence (Summing)• Random Coincidences• …

For What…?• Nuclear Structure• Environmental• Material• Nuclear Astrophysics• Medical• Industrial• …

• Composite detectors• Online vs. offline histogramming• Coincidence/anticoincidence• …

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

“Classical” Compton Suppression

• Online signal processing and hardware gating.• Anticoincidences. Kill good events !!!

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Detector Spheres• Cost• Room• Availability• Passive Shielding

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Detector Spheres

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

“Chronic” Corrections

• Geometry (Extended Source)• Self Absorption• True Coincidence Summing• Random Coincidences

Last Year !!

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Stellar Evolution (Overview)

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Thermonuclear Resonant Reactions

Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept. 2007.

Energy

Cro

ss s

ecti

on

EC

Resonance Strength

Low energy ?Barrier penetration

Yield 2 2 Background ??

QTarget

Projectile

Compound Nucleus

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Specific ProblemNeutron sources for the s-process

14N(, )18F(+)18O(, )22Ne(,n)

12C(p, )13N(+)13C(,n)

At temperatures of interest:• Reaction rate is dominated by 2 resonances; 470 & 566 keV.• Never observed directly !• Estimated resonance strengths. • Now: Improved detection sensitivity.• Measured resonance strengths.

18O +

770750660566470

22Ne

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

How … ?• Close Geometry • Granularity (if available)• Offline Analysis• Timing• Cosmic Suppression• Random Coincidences• Cascade Coincidences• Measured Corrections• Simulated Corrections• Avoid Calculations based on assumptions• …

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Experimental Setup for Accelerators

BGO

L ead shield

Beam

BGOClover

T arget

P las tic sc intillator

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Multiplicities

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Cosmic Suppression

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Random Coincidences

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Addback vs. Direct Mode

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Addback vs. Direct Mode

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Summing-in and -out

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Doppler Correction

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Various Modes of OperationIgnore scintillation No suppression.AnticoincidencesUse Pl. Scintillator Cosmic suppression.Use BGO Compton suppression.Coincidences (w/o cosmic suppression)Window on Clover + BGO Q-value gating.BGO window Cascade coincidences. Clover addback window Summing-in.Clover crystal window Summing-out.

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Ultimate Data Reduction• Cosmic suppression.• Cascade coincidences. • Random coincidences.• Signal-to-background ratio…!!!

Offline

01.27

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Detection Sensitivity

• Low-energy ultra-weak resonance.• 10 days beam on target.

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Detection Sensitivity

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Detection Sensitivity

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Detailed Coincidences

R

1.27

1 2 3 4

• Modes 1 & 2 are accounted for. Partial strength.• Bypasses over first excited state?

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

3-D Spectra

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

So what ?

• Improved detection sensitivity.• Bypass verification.• Weakest resonances detected.• Target stability.• Quantified reaction rate. Physical Review C 68, 025801 (2003)

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Setup for Small SamplesSample measured with 2 Clover detectors in close geometry.• Each Clover consists of 4 HPGe crystals.• Nearly 4π geometry High efficiency.

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Singles vs. Coincidences

Phys. Rev. C

69 025803 (2004)

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

• Close geometry summing.• Classical correction needs TOTAL efficiency • MC total efficiency• If MC why not MC Summing correction

Validate MCWhat about e

fficiency

for c

oincidence

s??

Monte Carlo (Remember 2006…!!)

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Correction Factor using Experimental Data

16 % in Direct Mode

Confirmed by MC

Nuclear Instruments and Methods in Physics ResearchA 517 (2004) 230-239

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Finally …

Get spirit of ideasand

apply to your setup

Invest in yourself

www.dababneh.com/yarmouk07

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Many Thanks

www.dababneh.com/yarmouk07

Acknowledgement

Franz Käppeler, Michael Heil, Rene Reifarth, Ralf Plag, Iris Dillmann, Michael Wiescher, Joachim Görres, Nikolas Patronis, Shawn

O’Brien.

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Saed Dababneh. Seventh Symposium on Use of Nuclear Techniques in Environmental Studies. Yarmouk University, JORDAN. 3-5 Sept.

2007.

Again: Addback vs. Direct